Theta blast cell

ABSTRACT

An underground blast shelter providing short and long term protection against nuclear detonation for its occupants. The shelter consists of a paraboloidal cell to house the occupants and a command station interfacing with the ground surface. A flange completely surrounds the cell along its long dimension. The command station is made from an upper portion made out of steel and a lower portion which is a part of the flange of the cell. Access between the command station and the cell is through the flange and includes foot wells to facilitate movement.

BACKGROUND OF THE INVENTION

This invention relates to a blast shelter and more particularly to apersonal blast shelter capable of providing improved protection duringand after the detonation of nuclear weapons and other disasters.

In my U.S. Pat. No. 4,660,334 issued on Apr. 28, 1987 I describe such ashelter capable of producing survival for its occupants during and afterone or more nuclear blasts regardless of where detonation takes placeexcept if the shelter is within or close to the crater formed by asurface blast. Such a shelter is capable of withstanding large doses ofneutron and gamma radiation, ground shock, and substantial overpressures, as well as a variety of other conditions, both short and longterm, enumerated in my patent.

SUMMARY OF THE INVENTION

In the present invention substantial improvements have been made in theblast shelter described in my patent identified above.

In order to increase the ability of the containment to resist the blasteffect resulting from the detonation of a nuclear device, the shape hasbeen changed and the construction of the connecting shaft below thecommand station has been improved in the ability of the system to absorbthe downward forces on the command station. In addition, the shelter hasbeen rendered more compact and less expensive to manufacture andinstall.

The present invention will protect a family unit, that is, shelterists,during disasters such as tornadoes, storms, forest fires, powerfailures, nuclear power plant accidents, nuclear terrorism, and a fullscale protracted nuclear, chemical, and biological war.

A number of other improvements have also been made to render the presentinvention the next generation of blast shelters of this type.

It is therefore a principal object of this invention to provide animproved and more compact nuclear blast shelter.

Other objects and advantages of this invention will hereinafter becomeobvious from the following detailed description of a preferredembodiment of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view in section partially illustrative of ashelter in place constructed in accordance with the principles of thisinvention.

FIG. 2 is a partially illustrative plan view of the shelter taken along2--2 of FIG. 1.

FIG. 3 is a right side view the shelter of FIG. 1 partially cut away.

FIG. 4 is a detail in section of the left side of the command stationshown in FIG. 1.

FIG. 5 is a top view of the command station shown in FIG. 1.

FIG. 6 is a view along 6--6 of FIG. 5.

FIG. 7 is a view along 7--7 of FIG. 5.

FIG. 8 is a view along 8--8 of FIG. 5.

FIG. 8a is a view similar to that of FIG. 8 showing an alternativeembodiment of the air input for the ventilation system, partiallyschematic.

FIG. 8b is a top view of the arrangement shown in FIG. 8a.

FIG. 8c is a view, partially schematic, along 8c-8c of FIG. 8b.

FIG. 9 is a schematic of the air infiltration system.

FIG. 10 is a section through the carbon filter shown in FIG. 9.

FIG. 11 is a schematic of the plumbing system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1, 2, and 3, there is shown a blast shelter 10consisting of a cell or containment 12 of paraboloidal configuration, acommand station 14 interfacing with ground level 16, and a passageway 18for providing communication between cell 12 and command station 14.

Cell 12, which is made from fiberglass, is of clam shell constructionconsisting of two clams shells 12a and 12b having rims 12c and 12d whichare joined to form a flange 20 completely surrounding cell 12 in itslong dimension. When the two clam shells 12a and 12b are placed togetheras illustrated, the two rims 12c and 12d are bonded and bolted togetherforming a fully enclosed unit with flange 20 covering the wholeperimeter of shelter 10 in its long dimension. By fiberglass herein ismeant fiberglass reinforced plastic (FRP) which is commerciallyavailable and typically is used to form the hulls of boats.

Each of the shells 12a and 12b includes one half of passageway 18 withmolded foot wells 22 formed to be used as steps to climb up passageway18. Since the diameter of passageway 18 is only about two feet, theopposite side of passageway 18 from foot wells 22 provides neededsupport for the climber.

Command station 14 consists of its lower part 14a which is an integralpart of clam shells 12a and 12b and thus is formed from two oppositelyfacing parts, and is part of the fiberglass construction of cell 12, andan upper part 14b which comprises a cylindrical body made from steel.

For details of how command station 14 is constructed in this manner,reference is made to FIG. 4. The upper part 14b of command station 14consists of a cylindrical section of steel the bottom part of whichterminates in a rim 24. The lower part 14a of command station 14terminates at the top in a rim 26 having an upwardly extending lip 28. Aplurality of annularly arranged bolts 32 through rims 24 and 26 hold theupper and lower portions of command station 14 together. A gasket 33 isemployed between the two rims. As previously noted, since lower part 14ais part of flange 20 surrounding cell 12, part 14a comes in twooppositely facing sections which come together to form the lower half ofcommand station 14 when clam shells 12a and 12b are joined together.

It will be noted that the lower part 14a of station 14 is provided witha shoulder 34 which flexes to absorb any forces transmitted from groundlevel through command station 14 to cell 12. Shoulder 34 is joined to aflared section which is illustrated. In addition, the fiberglassconstruction of the lower half of passageway 18 helps to absorb theseforces due to the ability of the material to flex.

The inside of upper part 14b of command station 14 is covered with alayer 133 of high temperature thermal insulation material to preventexcessive heat from building up inside the command station during asustained fire. The shelter itself is protected against this heat by theearth on top of the shelter. A sustained fire could develop when a housecollapses on the shelter and burns. The shelter is designed to resistfire reaching 1500 degrees F. during a three hour period. During thistime the shelter must be operated in a sealed shelter atmosphere.

It should be noted from FIGS. 1 and 4 that the construction of shelter10 extending down from the top of flange 20 is all fiberglass while theportion of shelter 10 extending from flange 24, namely, the upper partof command station 14 is steel. This construction maximizes strength andeconomy of manufacture and assembly.

Within shelter 10, referring to FIGS. 1-3, there is provided a unitarystructure 38 of fiberglass construction which includes stairs 42, acabinet 43 having a counter top 44, a bathroom 46 with a hand pumpedtoilet 47, and floors 48 and 52. The cabinet below top 44 and bathroom46 are provided with access openings 54 and 56, respectively. Bathroom46 is provided with shelving 58 to accommodate candles and the like.Floors 48 and 52 are provided with a number of trap doors 62 which arelifted to gain access to storage areas under the floors.

Unitary structure 38 is of single piece fiberglass construction which isinserted between clam shells 12a and 12b just before they are assembledand bonded and bolted together at their rims 12c and 12d.

Water tank 63 of shelter 10 is located under floor 52 at the far end ofthe shelter. The interior sides of tank 63 would have level markers toindicate volume in gallons which have been consumed and gallonsremaining in the tank.

Water is piped from tank 63 to sink 63a through a flexible hose (notshown). A manual faucet/pump (not shown) would be located on sink 63a.

Tank 63 is filled with water and chlorinated when shelter 10 isinstalled and can be stored for one year. The chlorine keeps bacteriaand algae from growing. The water is not potable (fit for drinking),however until it is properly filtered.

Because water tank 63 is below the frost level, it will not freeze. Oncea year the water must be replaced so that the shelter will always beready for immediate use in case of an emergency. Included in the shelteris an electric pump (not shown) which is capable of lifting the waterfrom the water tank 63 to the ground surface. Although the water in thetank is very cold and chlorinated, some invisible bacteria may developif not properly chlorinated making the interior walls slimy to thetouch. If this develops the water tank walls can be cleaned through thewater tank cover when the water is changed each year.

Filling the water tank during wartime or when there is no electricitywould be accomplished by siphoning water through a hose from a jug orbucket on the surface down the shelter entranceway through a waterfilter to remove particulates and/or radioactive fallout and into thewater tank.

Referring to FIGS. 5, 6, 7, and 8, it will be noted that the top ofcommand station 14 is dome shaped and provided with a cover 64 ofsmaller diameter having an extension 66 which is hinged on a pin 68through an elongated slot 70 for a purpose to be described below. Itwill be noted that the rim of cover 64 is provided with a lip 72 whichengages a shelf 74 having a shoulder 76 of annular configuration. Aflange 75 at ground level provides additional stability.

Adjacent extension 66 is a threaded opening 78 into which is threaded anexternal lock member 82 having an opening 83 for a padlock (not shown).Lock member 82 with its padlock would be employed when shelter 10 isunoccupied to prevent unauthorized entry. Member 82 prevents cover 64from being opened by blocking the pivoting of extension 66. The padlockwhen installed would prevent rotation and removal of member 82. Removalof lock member 82 permits access into shelter 10.

Referring particularly to FIG. 6, adjacent the hinge arrangement justdescribed is a dog mount 84 with a threaded extension 84a on which ismounted a dog 85 to tighten cover 64 down when closed from the inside.Dog 85 has an extension 85a riding on a wedge 85b. When dog 85 isrotated, cover 64 is clamped down. Slot 70 is elongated in order topermit this tightening to take place. Several dog mounts may beemployed.

One or more threaded openings 64a are provided in cover 64 to form lightports. A sight glass or a plug would be threaded into each opening 64a,as required, and, also, any one of these openings can be used to extenda radio antenna.

During daylight hours, sunlight is piped into the shelter through lightports 64a and reflected into the shelter. White glossy walls of theshelter provide ample brightness from this light.

Shelter use during wartime must depend on light other than daylightbecause there may be only 10 percent of the normal daylight during thefirst week and reduced light levels during the first month from theinjection of smoke and soot into the atmosphere.

As seen in FIGS. 5 and 7, there are provided one or more elongated slots86, as defense ports, each covered by a plate (not shown) which would bescrewed on over the opening from the inside using bolts 88a and 88b.

As seen in FIGS. 5 and 8, there is also provided an air intake port 92.Within command station 14 there is provided an upwardly extending pipe94 mounted on a pipe flange 96 and supported by an angle 97. Pipe 94terminates at 98 above the level of port 92. This is to prevent anywater entering port 92 from running into pipe 94. In the event of amassive flow of water, pipe 98 would be sealed off as will be describedbelow. A blast valve 102 is located within a conduit 103 which receivesthe air from port 92 and pipe 94. Valve 102 closes in the event airpressure rises above some threshold value, thereby blocking any blastwave from entering the shelter, or in the event water enters pipe 94.For exhaust port 104 there would be provided a blast valve (not shown)which is a simple check valve to permit air to be discharged but not toenter.

An alternative air intake arrangement with reduced resistance to airflow is shown in FIGS. 8a, 8b, and 8c. Command station 14' otherwiseidentical to station 14 described in the previous figures is providedwith an inlet port 92' located just above flange 75'. An angle 97' witha horizontal leg 97'a causes the incoming air as shown by the arrows inFIGS. 8a and 8b to enter horizontally, rise to go over the verticallyextending side of angle 97' and then flow down into a region 98' havingan opening 99' into blast valve 102' shown schematically. The region isboxed in with a U-shaped member 104 having an end wall 104'a. A sectionof an angle 106' directs the air into the region.

A schematic of the air infiltration system is shown in FIG. 9. There itwill be seen that within command station 14 is shown blast valve 102located adjacent opening 92 and a filter 106. Within cell 12 there islocated a carbon filter 108 and a blower 110 which would be manuallyoperated. Carbon filter 108 and blower 110 are located within cell 12with filter 108 typically on a counter top. Since filter 106 trapsradioactive particulates, it must remain in the command station. Filter106 is a simple mechanical filter consisting of a cloth bag made ofordinary felt to trap particulates.

Cross sectional details of filter 108 are shown in FIG. 10. Filter 108comprises a fiberglass housing 112 containing a layer of open-celledfoam 113 on the bottom (upstream side) of housing 112, a first filtercloth 114 located above foam 113, a layer of carbon particulate 115supporting a first filter cloth 114, and a second filter cloth 116located above carbon particulate 115 which fills the space betweenfilters 114 and 116. Above and supported by filter cloth 116 is anotherlayer of carbon particulate 117 filling the space up to a third filtercloth 118 located just above particulate 117. Finally, a second layer ofopen-celled foam 119 fills out the interior of housing 112.

The purpose of foam 113 is to prevent distortion of the filter clothsdue to the weight of the materials, especially when there is no airflow. Cloth 114 primarily supports the carbon particulate 115 but willalso catch any particulate missed by filter 106. Carbon particulate 115consists of activated carbon to remove any radioactive iodine gas whichmay be present.

Carbon particulate 117 consists of carbon particles impregnated toabsorb gaseous contaminates and specific toxins related to chemicalwarfare. Such material is available commercially.

Filter cloth 116 separating the two layers of carbon prevents theirbecoming intermixed.

Filter cloth 118 prevents carbon fines from being introduced into theshelter while foam 119 prevents cloth 119 from stretching out andpermitting the carbon particulate upstream from piling up in the center.

The open celled foam materials 113 and 119 are ordinarypolyvinylchloride (PVC) having an epoxy coating to provide stiffness andstrength and such material is available commercially.

Air blower 110 is operated by a hand crank and will deliver enough airvolume to completely replace all the air in the shelter in approximately6 minutes. To meet the breathing requirements air blower 110 has to beoperated only 10 minutes per hour per 5 adults.

If too little fresh air is pumped into the shelter the carbon dioxidelevels will reach 3% in about 6 hours with 5 adults in the shelter. Atthis level the shelterists may experience headaches. To prevent thisfrom happening a clock would be employed to remind the shelterists thatthe air blower has to be operated. There could be small streamers on theoutlet of the fan to confirm air being pumped into the shelter. Shouldthe air blower not be operated for longer than approximately 6 hours,for example, during sleeping periods, the shelterists may wake up with aheadache.

When there is an extensive fire directly on top of the shelter,superheated air from outside must not be pumped into the shelter byoperating air blower 110. The shelterists must then live in the shelterwithout fresh air coming into the shelter. This is called operating in asealed shelter atmosphere.

Most fires have a violent burning period up to about one hour and aretotally over in about three. The present blast cell has enough volume ofair to support 5 adults for a period of 6 hours when operating in asealed shelter atmosphere. There is no need for synthetic air duringthis period. To enable the shelterists to monitor the internaltemperature of the shelter a thermometer may be provided.

Shelter 10 is provided with a system to dispose of liquid wastes, andthe schematic is shown in FIG. 11.

Gray water, that is, water used in washing and showering, is collectedin sink 63a and by gravity passing through a filter bag 122 to collectsolid wastes and is delivered to a holding tank 124 located beneathfloor 48. Water from tank 124 is hand pumped for use in toilet 47 andhand pumped up to a septic tank 128 located in command station 14 inwhich the solids settle out to the bottom. As tank 128 fills up theliquid passes out into the leach field surrounding station 14 throughone or more perforated pipes 132. Suitable venting through one of theopenings in cover 64 may be provided, each opening being provided with ascrew on cover in case required.

At least one person each day must take a shower to provide enough graywater in the gray water holding tank 124 to flush toilet 47. Gray wateris water which is contaminated from washing dishes and bathing but notsewage. Showering in the shelter is very basic. A two gallon tank (notshown) is filled from the faucet in sink 63a. The tank with the filteredwater is hung on the cowling within bathroom 46 and the shelterist usesa hose from this tank to direct water over the body. The shower waterdrains down into the gray water holding tank 124 where it will be usedto flush toilet 47.

The gray water in holding tank 124 is not potable. This system allows amuch smaller water supply rather than wasting potable water to flush thetoilet. The toilet has a small hand pump (not shown) which provides theforce to push the sewage up to the septic tank. The sewage hose iscompletely accessible and is connected to the septic tank in commandstation 14.

Septic tank 128 has a volume of 10 gallons and proportionately conformsto standard building codes which allows the water portion of the sewageto drain off and the poisonous gases which develop from decomposition tovent to the outside through one of the ports in the top of commandstation 14. The sanitation system in shelter 10 is designed to last onemonth before it will require dumping. When septic tank 128 is full, itis taken outside through the command station hatch where the septic tankcover is removed and then dumped.

The blast shelter would be supplied with long life candles, typicallyeach having a burning time of 150 hours. This is a simple, safe andefficient way of lighting. In common building structures where the wallsare flat, high, and have a rough surface texture, a candle is notadequate. However, in the present shelter, the walls are curved, white,and smooth resulting in a simple candle providing adequate light.

The invention as described above, in a typical size, is a totally selfcontained, paraboloid nuclear blast shelter designed for five adults tobe personally owned by a single family. It can be installed above orbelow the water table and does not require electricity to operate. Asnoted, the shelter is made of structural fiberglass and steel. Theinside is smooth and white to create maximum brightness with minimallight. It has its own air filtration system, water supply, septicsystem, light, sleeping area, exercise area, and storage area, all ofwhich will function without electricity. These facilities are allprovided for in a sterile environment and the shelter can be installedin almost any part of the world.

Cell 12 is a fiberglass structure composed of multiple compound curves.Fiberglass is chosen as the optimum material because of itscharacteristics for a blast resistant structure placed below ground. Afiberglass structure is completely watertight and proven to be sound inthe boat and underground storage tank industries. In addition, one ofthe greatest characteristics of fiberglass is it resiliency. It can beoverstressed and return to its normal shape with no structural damageand has a life span of hundreds of years. It can also be repaired veryeasily by the owner. A fiberglass structure can be designed withmultiple compound curves on all three axis making it extremely strong.

Cell 12 in effect is a pressure vessel designed for external pressure,not internal pressure. A structure which is round and placed underinternal pressure like a pipe will maintain its shape, but a structurewhich is placed under external pressure tends to lose its shape andtherefore its structural integrity unless it is designed specificallyfor external loading subject to buckling. In the present invention thepressure vessel is subject to external pressure rather then internalpressures.

Shelter 10 would come with a survey meter to measure the radiation rate.For shelters which are directly downwind of ground zero, 94% of thetotal radiation will have decayed after the first week and 99% will havedecayed by the 28th day. After the 28th day the radiation levels arenear normal levels and normal living can resume including functions suchas dumping sewage. The actual time will probably be less and will dependon the size of weapon, type of burst, height of burst, weather, andterrain. A survey meter available within the shelter enables theshelterists to determine the actual radiation level and thus determinehow long they will have to stay in the shelter. During this 28 dayperiod, shelterists can come out of the shelter for brief periods tomake radiation measurements and otherwise examine the state of theenvironment.

The absence of chemical and biological warfare agents and enemy infantryshould be verified before leaving the shelter. This can be accomplishedin two ways. The first way is listening to emergency radio broadcaststations reporting the location of the enemy and types of tacticalweapons being used. The radio in the shelter would be powered by a smallbattery. The blast shelter battery operated AM, FM, Short wave radioallows the shelterist to listen to broadcasts on frequency bands in theU.S. and other countries. To use the radio it is necessary to stick theradio antenna out of a defense port of the command station.

The second way is to look through the view ports to verify animal lifesuch as birds, dogs, cats, etc. All animals should be observed for atleast 24 hours.

Heating in the shelter is provided by the heat loss of the shelterists.The shelter being in the earth is much more stable during outsidetemperature fluctuations than in an above ground structure. Heating israrely a problem in an underground structure. For this reason the blastshelter has no insulation.

Cooling in the shelter is provided by a greater volume of air beingpumped into the shelter. The exhausted air is also removed at the top ofthe shelter. Air blower 110 should be capable of supplying 20 cubic feetper minute for each shelterist which will allow a maximum internaltemperature of 75 degrees F. not accounting for the mass of thesurrounding earth. With the volume of the shelter being so large and somuch earth covering the shelter, the inside temperatures would be quitecomfortable. This particular engineering design eliminates the typicalproblem of the shelter overheating.

While only preferred embodiments of this invention have been describedit is understood that many variations of the invention are possiblewithout departing from the principles of this invention as designed inthe claims which follow.

What is claimed is:
 1. An underground nuclear blast sheltercomprising:a. elongated cell means below ground level containing livingspace for one or more occupants of said shelter; b. underground commandstation means located above one end of said cell means having a dome atground surface and passageway means extending directly down into thecell means for providing access through the bottom of said commandstation means to said cell means, said dome being the only visibleportion of said shelter; c. said cell means comprising a pair ofmatching elongated clam shaped elements having matching rims extendingalong the edges thereof, said matching rims bonded to each other to forma flange completely encompassing said cell means along the longdimension thereof; d. said command station means comprising a lowerportion formed within and being an integral part of said flange formedby said clam shaped elements, said flange extending above the cellmeans, and an upper portion extending above said flange, means joiningsaid upper and lower portions of said command station means to form anenclosed area; and e. said passageway within and being an integral partof said flange formed by said clam shaped elements to provide saidcommunication between said command station means and said cell means. 2.The shelter of claim 1 wherein said cell means is paraboloidal inconfiguration.
 3. The shelter of claim 1 wherein said command stationmeans includes conduit means extending out from said upper portion fordistributing liquid waste products into a surrounding leach field formedbelow ground level.
 4. The shelter of claim 1 wherein said commandstation includes means within said lower portion for absorbing verticalfaces on said dome.
 5. The shelter of claim 1 in which said domeincludes air inlet and outlet openings, a light port, and a defenseport.
 6. The shelter of claim 1 in which the inner surface of the upperportion of said command station means is lined with fire insulation. 7.The shelter of claim 1 in which the inner surface of said cell means issmooth, curved, and painted white to make most effective use of a smallsource of light.
 8. The shelter of claim 1 wherein said cell meansincluding said flange and the lower portion of said command stationmeans are concentrated out of fiberglass.
 9. The shelter of claim 8wherein the upper portion of said command station means is metallic inconstruction, said joining means comprising matching rims in said upperand lower portions for joining said portions together, said commandstation means thereby being a composite of fiberglass and metal.
 10. Theshelter of claim 1 in which said passageway means includes foot wallsformed within said flange by said clam shaped elements to facilitatemovement between said cell means and said command station means.
 11. Theshelter of claim 10 having unitary structure means for mounting betweensaid clam shaped elements during assembly to form said cell means, saidstructure means including steps for permitting said occupants to climbsufficiently high to make contact with said foot walls.
 12. The shelterof claim 1 in which the upper portion of said command station meansincludes ventilation means for taking in fresh air and means fordischarging exhaust air.
 13. The shelter of claim 12 having means toblock water seepage into said command station means.
 14. The shelter ofclaim 12 in which said ventilation means includes valve means to preventblast waves from entering said shelter.
 15. The shelter of claim 14 inwhich said ventilation means includes first filter means within saidcommand station means to trap particulates in incoming fresh air andsecond filter means within said cell means to remove from said fresh airdetrimental gaseous components from said fresh air.
 16. The shelter ofclaim 15 in which said second filter means comprises a first bed ofactivated carbon means to remove any radioactive particulate not trappedby said first filter means and a second bed of carbon means to absorbgaseous contaminants related to chemical warfare.
 17. The shelter ofclaim 16 having a first filter cloth to separate the two beds of carbonto prevent intermingling.
 18. The shelter of claim 17 having a secondfilter cloth upstream of said carbon means to support the adjacentcarbon means.
 19. The shelter of claim 18 having a third filter clothdownstream of said carbon means to trap carbon fines.
 20. The shelter ofclaim 19 having open celled foam means both upstream of said secondfilter cloth and downstream of said third filter cloth to preventdistortion of said filter cloths and redistribution of said carbonmeans, said open celled means being coated with an epoxy to providestiffness.